Re: GUI doesn't appear when using ./run-octave

[Philip Nienhuis]

Michael D. Godfrey wrote:
> On 09/22/2012 04:32 AM, Torsten wrote:
> > What about a command line option that controls which other settings file
> > is used, e.g. --settings-file FILE?
> This, at least for systems that support alias or its equivalent, will
> allow users to configure any combination of versions and settings.
> Seems like a pretty simple and natural approach.

Still, even to just avoid support questions, Octave version #A should 
not "hang" or bail out on incompatible settings file formats (e.g., for 
Octave version #B) if an unwary user forgets to (or cannot) issue that 
command line option.
Remember, GUIs are regularly started from a start menu or desktop launch 
thingy where command line options are very easily forgotten or hard to 
add. Such start menu items or desktop launchers are often included with 
distribution-specific installer files (.deb, .rpm, etc) that usually 
don't know about local system setup idosyncrasies either.

My idea was rather that each Octave version would search the settings 
file for the settings it needs, and
a- uses the settings it finds and knows about;
b- uses defaults for settings it does not find;
c- ignores settings it doesn't recognize or doesn't know how to invoke.

For cases b or c some warning might be issued.

Maybe Octave should remember if it found an incompatible settings file 
format and in that case warn the user when he/she is about to save new 
settings (to avoid overwriting settings for a possible other Octave 
version on the same machine).

Another solution: a settings file could have several sections separated 
by a version number header. Or maybe the version number should be a 
"setting", to be recognized by Octave so it can decide what to do next.

Anyway, I think such a mechanism should be in place regardless of the 
command line solution (which IMO is a useful addition).

Long time ago I wrote stuff like this for some SW I developed. I 
remember that while it looked easy at first sight, it turned out there 
were loads of gotchas and that devising a robust mechanism for saving to 
and reading from settings files requires careful thinking.

Philip